Koa-req-logger NPM

Introduction

A simple logging middleware for the koa http framework for nodejs. This module uses the pino logger and was inspired by the koa-pino-logger module. This module was created with typescript, and is compatible with both javascript and typescript projects.

As well as logging requests and providing a log object in requests, this module also sets the HTTP Headers Date, X-Response-Time and X-Request-ID.

X-Request-ID Header is set to a new uuid or the value of the X-Request-ID header sent with the request. This allows requests to be tracked through microservices.
Date Header is set to the date and time that the request was received.
X-Response-Time Header is set to the response time of the request in milliseconds.

Install

yarn add koa-req-logger
npm install koa-req-logger

Usage

For a full API Reference see the documentation here⇗.

TypeScript

import Koa from 'koa';
import { KoaReqLogger, KoaReqLoggerOptions } from 'koa-req-logger';

const opts: KoaReqLoggerOptions = {
  disableIdHeader: false;
};

const app = new Koa();
const logger = new KoaReqLogger(opts);
app.use(logger.getMiddleware());

app.use((ctx, next) => {
  ctx.log.info('Some Log Message');
  ctx.log.warn({ obj: 'object' }, 'Log a message with an object');

  ctx.throw(400, 'Bad Request');
});

app.listen();

JavaScript

const Koa = require('koa');
const { KoaReqLogger } = require('koa-req-logger');

const app = new Koa();

const logger = new KoaReqLogger();
app.use(logger.getMiddleware());

app.use((ctx, next) => {
  ctx.log.info('Some Log Message');
  ctx.log.warn({ obj: 'object' }, 'Log a message with an object');

  ctx.throw(400, 'Bad Request');
});

app.listen(3000);

Output

Produces a similar output to the following json, which can then be parsed with pino's shell utility to pretty-print the output.

{"level":30,"time":1532251116578,"msg":"::1 - GET /","pid":4992,"hostname":"server.local","id":"ff0bae4b-b067-4cd6-8b99-5d221e74c515","req":{"method":"GET","url":"/","headers":{"host":"localhost:3000","connection":"keep-alive","upgrade-insecure-requests":"1","user-agent":"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36","accept":"text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8","accept-encoding":"gzip, deflate, br","accept-language":"en-GB,en-US;q=0.9,en;q=0.8"}},"startDate":"Sun, 22 Jul 2018 09:18:36 GMT","v":1}
{"level":30,"time":1532251116579,"msg":"Some Log Message","pid":4992,"hostname":"server.local","id":"ff0bae4b-b067-4cd6-8b99-5d221e74c515","v":1}
{"level":40,"time":1532251116579,"msg":"Log a message with an object","pid":4992,"hostname":"server.local","id":"ff0bae4b-b067-4cd6-8b99-5d221e74c515","obj":"object","v":1}
{"level":50,"time":1532251116583,"msg":"::1 - GET / - 400 4ms","pid":4992,"hostname":"server.local","id":"ff0bae4b-b067-4cd6-8b99-5d221e74c515","res":{"status":400,"headers":{"x-request-id":"ff0bae4b-b067-4cd6-8b99-5d221e74c515","date":"Sun, 22 Jul 2018 09:18:36 GMT","x-response-time":"4ms","content-type":"application/json; charset=utf-8"}},"err":{"type":"ClientError","message":"Bad Request","stack":"BadRequestError: Bad Request\n    at Object.throw (/home/drbarnabus/Development/test-service/node_modules/koa/lib/context.js:96:11)...","status":400,"statusCode":400,"expose":true},"responseTime":4,"startDate":"Sun, 22 Jul 2018 09:18:36 GMT","v":1}